3,3'-methylenebis[5-methyloxazolidine]

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study according to guideline (OECD 306) in compliance with GLP (without certificate). The pollutional and nutritional status of the seawater is not described in the study report. 2 replicates for both test item and reference substance and 5 replicates for the blank control were used, instead of each 8 proposed by the Guideline. No toxicity control was run. O2 consumption in the control vessels was slightly higher (mean 35%) than decribed in the Guideline (30%). However, these deviations are not expected to have a significant influence on the conclusion. Therefore, the test is considered to be valid. Seawater sample was not fully described (depth of collection, DOC), description of stock solution is incomplete, possible interference from oxygen uptake by nitrification was not addressed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 306 (Biodegradability in Seawater)

Version / remarks:

(Closed Bottle Procedure)

Deviations:

yes

Remarks:

Pollutional and nutritional status of seawater not reported. 2 replicates for test item and reference and 5 replicates for blank were used instead of 8 each. No toxicity control was run. O2 cons. in control slightly higher than decribed in Guideline.

GLP compliance:

yes

Remarks:

No certificate but a Quality Assurance Statement is available

Test material

Test material information

Constituent 1

Reference substance name:

3,3'-methylenebis[5-methyloxazolidine]

EC Number:

266-235-8

EC Name:

3,3'-methylenebis[5-methyloxazolidine]

Cas Number:

66204-44-2

Molecular formula:

C9H18N2O2

IUPAC Name:

3,3'-methylenebis[5-methyloxazolidine]

Details on test material:

- Reaction products of paraformaldehyde and 2-hydroxypropylamine (ratio of 3:2)
- Specification: GrotaMar 71®

Specific details on test material used for the study:

The original study refers to MAR 71 as test substance.

Radiolabelling:

no

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: Natural seawater

Details on inoculum:

- Sampling site: MAFF site at Conway, North Wales (UK)
- Laboratory culture: No
- Pretreatment: Seawater (pH 8.12) was coarse filtered, maintained in the dark. Aged prior to use by gentle aeration for three weeks at 20 ± 2°C.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

2.5 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST SYSTEM
- Culturing apparatus: BOD bottles, 272 mL, completely filled
- Number of culture flasks/concentration: 2 (test item and reference substance) 5 (control)

TEST CONDITIONS
- Composition of medium: According to Acer Environmental SOP III.36
- Additional substrate: The seawater was fortified with nutrients (no data about nature and amounts)
- Test temperature: 20 ± 1°C
- pH: 8.12 at collection
- Salinity: 29.9 per mil
- Aeration of dilution water: No

SAMPLING
- Oxygen measured at days 0, 5, 10, 15, 22, and 28

CONTROL AND BLANK SYSTEM
- 5 control vessels without test substance

STATISTICS
- Mean values of replicated were used for calculations

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

Initial concentration 2 mg/L

Results and discussion

% Degradation

% Degradation 1

% Degr.:

69.4

Parameter:

DOC removal

Sampling time:

28 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 2.5 mg/L)

% Degradation 2

% Degr.:

71.4

Parameter:

DOC removal

Sampling time:

22 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 2.5 mg/L)

% Degradation 3

% Degr.:

62.6

Parameter:

DOC removal

Sampling time:

15 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 2.5 mg/L)

% Degradation 4

% Degr.:

27.4

Parameter:

DOC removal

Sampling time:

10 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 2.5 mg/L)

% Degradation 5

% Degr.:

11.3

Parameter:

DOC removal

Sampling time:

5 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 2.5 mg/L)

% Degradation 6

% Degr.:

53.8

Parameter:

DOC removal

Sampling time:

28 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 5.0 mg/L)

% Degradation 7

% Degr.:

62.8

Parameter:

DOC removal

Sampling time:

22 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 5.0 mg/L)

% Degradation 8

% Degr.:

56.8

Parameter:

DOC removal

Sampling time:

15 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 5.0 mg/L)

% Degradation 9

% Degr.:

8.3

Parameter:

DOC removal

Sampling time:

10 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 5.0 mg/L)

% Degradation 10

% Degr.:

8.3

Parameter:

DOC removal

Sampling time:

5 d

Remarks on result:

other: calculated as BOD/COD (Initial concentration 5.0 mg/L)

Results with reference substance:

77.5 % BOD/ThOD after 28 days

Any other information on results incl. tables

If BOD is related to ThOD _NO3 (2.577 mg O₂/mg) than after 28 days degradation is 48.7% (2.5 mg/L) and 37.7% (5 mg/L).

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

yes

Conclusions:

The substance reached the pass-levels for biodegradation. The substance has a potential for biodegradation in seawater.

Executive summary:

The results indicate that the substance has a potential for biodegradation in seawater at both concentrations. After 28 days of incubation, the degradation (calculated as BOD/COD) was 69.4% at 2.5 mg/L and 53.8% at 5.0 mg/L. However, the higher concentration (5 mg/L) had also achieved 62.8% degradation by day 22 at which point almost all the oxygen had been consumed. The pass level was reached within 14 d at both concentrations. All other validity criteria of the OECD Guideline were met.

During the study, the COD was measured to be 1.8089 mg O2/mg. This value is similar to the ThODNH3 of 1.89 mg O2/mg when nitrification is not considered. For total oxidation a ThODNO3of 2.58 mg O2/mg is calculated. The degradation percentages calculated on the latter value, where nitrification is considered, would be lower. The pollutional and nutritional status of the seawater is not described in the study report. However, the O2consumption in the control vessels was slightly higher (mean 35%) than described in the Guideline (30%) which might be caused by nutrients present in the seawater. This small deviation is considered to have no significant influence on the test results. In the study 2 replicates for both test item and reference substance and 5 replicates for the blank control were used, instead of each 8 proposed by the Guideline. This deviation is considered to have no significant influence on the test results. No toxicity control was run. However, results from tests on inhibition to microbial activity  indicate that the test was conducted in a non-toxic concentration range, the EC50was determined to be 44 mg/L in both tests.

Studies on hydrolysis of the substance  indicate that at large dilutions the hydrolysis products are expected which are both readily biodegradable. Therefore, the substance and the hydrolysis products are expected to be extensively removed in biological treatment plants as well as in environmental compartments.

The constituents of the reaction product (substance) are not volatile from aqueous solutions, therefore this removal mechanism could not influence the test results. It is not expected that the low adsorptivity of the test substance influenced the oxygen uptake.